Difficulties with free field ground motion analysis

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Roy Michel
Posts: 6
Joined: Thu Mar 08, 2007 5:27 am
Location: Trondheim, Norway

Difficulties with free field ground motion analysis

Post by Roy Michel »

Hi!

I'm a MSc student doing my Master Thesis this spring. I'm trying to do a free field ground motion analysis in OpenSees, but I'm having some trouble generating the proper input file.

I think that I have omitted one or more vital parts in the model building.

I have defined the following:

- nodes
- fixities
- nD material for the soil
- quad elements
- equal DOF
- recorders
- the dynamic ground motion analysis

When I run the analysis, it doesn't converge (I suppose that the whole thing just "fails" due to some singularity)

Can anyone tell what I have omitted?

I also have a hard time finding educational examples for free field ground analysis in OpenSees, does anyone have advise where I can find some examples?

Thank you very much!


-Roy, probably the only soul in Norway working with OpenSees :D
fmk
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Location: UC Berkeley
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Post by fmk »

if it fails at the first step due to a problem with the solver it means that you do not have enough constraints in your model.
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